This invention relates generally to an apparatus for testing psychomotor capability and, more specifically, to an apparatus for testing intoxication levels.
Devices interconnected with the ignition systems of motor vehicles to test for sobriety prior to vehicle operation are known. However, the prior art devices measured sobriety by performance of one or more of the following types of tasks: simple jump reaction, pursuit tracking, compensatory tracking, divided attention, mental arithmetic coupled with keyboard entry, digit span memory with keyboard entry, and visual flicker discrimination. Unfortunately all of these techniques have at least one of the following disadvantages. They require extensive training of a subject or they test and therefore discriminate on skills not pertinent to driving, such as numerical ability, in addition to discrimination of intoxication. Therefore, they sometimes do not effectively discriminate sober from intoxicated performance. Furthermore, with respect to several tasks mentioned above, as for example jump reaction and mental arithmetic, the performance level in the sober state varies widely among individuals, therefore necessitating the setting of thresholds for each user rather than using a universal threshold. Obviously individual threshold settings present a problem if the equipped vehicle is to be driven by more than one person.
It is the object of this invention, therefore, to provide test equipment that will both more accurately measure those skills pertinent to driving behavior and more effectively discriminate between sober and intoxicated performance.